Artificial-tooth crown and bridgework.



J. B. RIGHTER. ARTIFICIAL TOOTH GROWN ANDBRIDGEWORK.

APPLIGATION FILED AUG. 9, 1906.

PATENTED DEG. 17, 1907.

- UNKTE %TATE% FATENT 'KOFFICE.

JAMES B. RIGHTER, RIVER FALLS, WISCONSIN.

ARTIFIGIALTOOTH CROWN AND BRDGEWQBK.

Specification of Letters Patent. 7

Application filed August 9.1903. Serial No. 329.932;

To aZZ-whom'it may concern:

Be it known .that'I, JAMES B. RIGHTER, a citizen of the United States,residin at River Falls, in the county of Pierce an State of Wisconsin,have invented a new and useful ArtificialeTooth Crown and Bridgework, ofwhich the following is a specification.

This invention relates to means for securin artificial teeth in place,and is clearly apphcable either to single crowns or bridge I work.

without the necessity of submitting the or-- celain or tooth elements'toheat, and t us eliminating to a very material degree, the

I danger of cracking, fracturing or-discolormg, the porcelains duringthe'manufacture of the crown or bridge.

In the drawings :Figure 1 is a front elevation of a bridge, constructedin accordance with'the present invention. Fig. 2 is a horizontalsectional view on the line 22 of Fi .1. Fig. 3 is a vertical sectionalview on the 33 of Fig. 2. Fig. 4 is a front elevation of a' portion ofthe backing strip, illustrating the manner in which the toothelementsare positioned. Fig. I 5 is a detail perspective view of a crownstructure; Fig. 6 is a horizontal sectional view therethrough. Fig. 7 isa vertical sectional view throu h the em.- bodiment illustrated in Fig.5.. i.-8 is a detail perspective view of one of t e tooth dummies.

Similar reference numerals designate corresponding parts in all thefigures, of the I drawings.

Referring first to the embodiment illustrated in Figs. 14 inclusive,spacedroot. engaging pins 8 of any well known construction are providedand are carried by copin s 9. These copings are connected by a bac ingstrip composed of a series, of sections or L lates 10 arranged edge toedge, each plate Being provided with a socket 11 extending from theinner edge and terminating short of the outer edge. The sockets aredovetailed or undercut, as shown at 12, and'preferably, though notnecessarily taper toward their outer ends. The various plates areentirely Patented Dec. 17, 1907." I

separate andinde endent'elements, but 'in theman-ufacture o the bridgeas hereinafter' described, they are soldere gether by w a metallic orother investment 13 Fig. 2. are designated by the reference numeral lfy,and are of porcelain or othersuitable material. These tooth dummies haveflat rear faces 16- that a-but against the front faces of the plates orsections 10. The tooth d ammies carry pairs of rearwardly extending pins17, preferably embedded in the thickest por tions of the elements,though they maly be 3 or fastened to- .60 that is flowed against therear, faces thereof, said lnvestment entering the dovetailed or undercutrecesses 14, formed between .theadacent walls of the sockets 11, asshown :in.

Tooth dummies or porcelain facings' 65.

placed at any distance from the ends 0 the Y teeth as desired. Thesepins are rovided at thelr outer or pirojecting ends wit heads 18 whichinterlo ner ends and moved outwardly into inter- Fig. 4, being finallycemented in.pla'ce in a manner well understood.

tooth dummies and metal backings are In the manufacture of a bridge, thedesired in the undercut portions of the sockets 11, the heads beingadapted to be passed-laterally into the sockets at their in-' lockingengagement, as clearly illustrated in placed together with the pins ofthe former engaged in the sockets of the latter, and the parts aredummies are removed, an any form of suitable investment used in makingthis character of'work is run in carefully, the copings position. Theporcelain facing or tooth dummies 15 are then replaced, andcementdi'sclosed. In the first place, the bridge can be constructedWithout submitting the porcelain elements to heat, thereby avoiding thedan er of discoloration and fracture. The tootli dummies or orcelainfacings are furthermore thoroug y reinforced by the metal backing sothat the stress from biting is ef fectively withstood Without damage.The projectin pins, bein formed in the thickest portion 0 the toothummies, do not Weaken the same as in the structures now in common use,wherein sockets are formed in said dummies. Moreover, by having the pinsin the thicker portions, they'can be set more deeply in the porcelain,and thus have greater anound to suit the bridge. These J parts are t enWaxed into (position, the tooth and root-engaging pins beingalso securedin ed, thus completing the structure. There: are many advantages for thearrangement unite these elements with the backing. In

- this'connection, it will be observed that the pins, effectivelysecuring them in place.

said cementengages between and around tllie n case-of in"ury, repairsmay be more readily made to t eparticular part affectedwithout thenecessity of altering or deranging the other elements or arts.

. Thatthe invention is as fully applicable to crowns-will be evident byreference to Fix :5. 5, 6 and 7, of the drawings,-wherein a slightr Tmodified form of construction is illustrated. Theroot-engaging pin isshown at 19, and is connected to a co ing or cap 20, the cap carrying anoutstan ing backm plate 21 reinforced by investment 22. While a singlesocket may be provided in the backing plate as in the first describedconstruction, a double socket may be employed if desired, and as shownat .23, the sections of the socket are in the form of outwardly tapereddovetails, said dovetails extending from the inner end of the backinglate and terminating short of the outer end thereof. It will be evidentthat this structure, including the method of nianufacture, andvtheadvantages arising therefrom, is substantially the same as that firstsetforth, so that a further description is believed to be unnecessary.

From the foregoing, it is thought that the construction, .operation, andmany advantages of the herein described invention will be apparent tothose skilled in the art, without ther description, and it will beunderstood that various changes in the size, shape, proportion, andminor details of construction, may be resorted to without departing fromthe s irit or sacrificing any of the ad vantages o the invention.

Havin thus fully described my invention, What I c aim as new, and desireto secure by Letters Patent, is

1. In tooth crown and bridge Work of the character described,tl'le'combination with a coping, of a backing plate located upon thecopin and having an undercut socket in its front ace, investment locatedin rear of the plate and upon the coping and securmg'the two together,and a tooth dummy havm aagainst the front side of the stri and havingprojections on their rear sides t at are interlocked in the said socketsof thesections.

3. In tooth crown and bridge Work of the character described, thecombination with spaced root-engaging pins, of copings mounted thereon,a backing strip connecting the copings and comprising a series ofsections, each section having an undercut socket extending from itsinner end and terminating short of its outer end, investment connectingthe sections on their rear sides, and tooth dummies located against thefront side of the strip andhaving rearwardly projecting headed pins thatinterlock in the undercut sockets. 4. In tooth crownand bridge Work ofthe character described, the combination with a backing strip comprisinga plurality of separate sections, of investment securing the sectionstogether edge to edge, tooth dummies interlocked with the front sides ofthe sections, and tooth engaging devices for securing the strip inplace.

n testimony, that Iiclaim the foregoing as my own, I have hereto aflixedmy signature in the presence of two Witnesses.

JAMES B. RIGHTER.

W'itnesses:

W. P. KNOWLES, L. H. ASHLEY.

